1. Field of the Invention
This invention relates generally to fire prevention sprinkler systems for buildings and warehouses and more particularly to a more economical means for installation of such systems.
2. Description of Related Art
Buildings and warehouses are required to have inside fire preventive sprinkler systems which are typically of the water dispensing type through a plurality of sprinkler heads positioned in close proximity to the inside surface of the roof for maximum effectiveness. These typical fire prevention systems include elongated main water feed lines which extend along the base or lower margin of each roof panel and include sprinkler head mechanisms attached in space relationship along pipe feed lines which extend orthogonally from each main water line upwardly alongside and in close parallel relationship to the roof.
To establish the fluid connection between the lower end of each of these feed lines and the main water supply line, a series of three fittings are required due to the fact that each roof panel is sloped at a standard pitch angle which may vary from 1:12 to 6:12 in pitch. The sprinkler system installers are typically armed only with 90° and 135° elbows and straight short nipple fittings so that, to fabricate each such joint between the feed tubes and the main water supply line, two 90° elbows and an interconnecting short straight nipple attached to an uprightly connected nipple tap into the main water line are required.
A number of prior art devices deal generally with fittings for water sprinkler systems installed into buildings and warehouses as follows:                U.S. Pat. No. 5,609,212 to McHugh        U.S. Pat. No. 5,669,449 to Polan, et al.        U.S. Pat. No. 6,540,261 to Painter        U.S. Pat. No. 6,450,264 to Christian        U.S. Pat. No. 6,523,616 to Wallace        U.S. Pat. No. 6,719,214 to Shaffer        
U.S. Pat. No. 5,669,449 to Polan, et al. discloses directional sprinklers designed for optimum operation over certain ranges of pitches and are envisioned to be within about 25° of the pitches from the overhead walls under which such sprinklers are installed.
Shaffer teaches a fire-extinguishing device in U.S. Pat. No. 6,719,214 and a sprinkler system is disclosed by Christian in U.S. Pat. No. 6,450,264. Fire sprinkler piping system fittings are taught by Painter, et al. in U.S. Pat. No. 6,540,261, and a building fire extinguishing system is disclosed by Wallace in U.S. Pat. No. 6,523,616. McHugh teaches adjustable sprinkler head positioning assemblies in U.S. Pat. No. 5,609,212.
An additional shortcoming of the standard fire sprinkler system in buildings and warehouses which have a peaked roof is also related to the unavailability in other than 90° and 45° (135°) elbow fittings. The roof peak of a sloped roof will necessarily have a correspondingly angled peak angle which will virtually certainly not match either of the standard elbows available. Due to this shortcoming in pipe fitting elbow availability, the interconnection between the upper ends of the upwardly sloping roof feed lines are left unconnected and terminate just short of the roof peak. This necessarily creates what may be referred to as a “tree system” wherein each of the main feed water supply lines provide water only to the feed lines extending upwardly on one of the roof panels while a second main water feed line provides water to be fed into the parallel array of feed lines attached to the other roof panel. Because the feed lines are dead ended or form a “tree system” the main water supply line must be of larger size and therefore more expensive in order to provide the required minimum level of water pressure and volume to the sprinkler heads when the system is energized in an emergency.